Discovery of orally bioavailable phenyltetrazolium derivatives for the acute treatment and the secondary prevention of ischemic stroke.

The potential for secondary stroke prevention, which can significantly reduce the risk of recurrent strokes by almost 90%, underscores its critical importance. N-butylphthalide (NBP) has emerged as a promising treatment for acute cerebral ischemia, yet its efficacy for secondary stroke prevention is hindered by inadequate pharmacokinetic properties. This study, driven by a comprehensive structural analysis, the iterative process of structure optimization culminated in the identification of compound B4, which demonstrated exceptional neuroprotective efficacy and remarkable oral exposure and oral bioavailability. Notably, in an in vivo transient middle cerebral artery occlusion (tMCAO) model, B4 substantially attenuated infarct volumes, surpassing the effectiveness of NBP. While oral treatment with B4 exhibited stronger prevention potency than NBP in photothrombotic (PT) model. In summary, compound B4, with its impressive oral bioavailability and potent neuroprotective effects, offers promise for both acute ischemic stroke treatment and secondary stroke prevention.

Methylated chalcones are required for rhizobial nod gene induction in the Medicago truncatula rhizosphere.

Legume nodulation requires the detection of flavonoids in the rhizosphere by rhizobia to activate their production of Nod factor countersignals. Here we investigated the flavonoids involved in nodulation of Medicago truncatula. We biochemically characterized five flavonoid-O-methyltransferases (OMTs) and a lux-based nod gene reporter was used to investigate the response of Sinorhizobium medicae NodD1 to various flavonoids. We found that chalcone-OMT 1 (ChOMT1) and ChOMT3, but not OMT2, 4, and 5, were able to produce 4,4'-dihydroxy-2'-methoxychalcone (DHMC). The bioreporter responded most strongly to DHMC, while isoflavones important for nodulation of soybean (Glycine max) showed no activity. Mutant analysis revealed that loss of ChOMT1 strongly reduced DHMC levels. Furthermore, chomt1 and omt2 showed strongly reduced bioreporter luminescence in their rhizospheres. In addition, loss of both ChOMT1 and ChOMT3 reduced nodulation, and this phenotype was strengthened by the further loss of OMT2. We conclude that: the loss of ChOMT1 greatly reduces root DHMC levels; ChOMT1 or OMT2 are important for nod gene activation in the rhizosphere; and ChOMT1/3 and OMT2 promote nodulation. Our findings suggest a degree of exclusivity in the flavonoids used for nodulation in M. truncatula compared to soybean, supporting a role for flavonoids in rhizobial host range.

Monitoring drug metabolic pathways through extracellular vesicles in mouse plasma.

The ability to monitor the response of metabolic enzymes to drug exposure in individuals is highly appealing and critical to personalized medicine. Although pharmacogenomics assesses genotypic differences, it does not report changes in metabolic enzyme activities due to environmental factors such as drug interactions. Here, we report a quantitative proteomics strategy to monitor drug metabolic pathways by profiling metabolic enzymes in circulating extracellular vesicles (EVs) upon drug exposure. Mass spectrometry (MS)-based measurement revealed that changes in metabolic enzyme abundance in EVs paralleled those in hepatic cells isolated from liver tissue. Coupling with multiplexed isotopic labeling, we temporally quantified 34 proteins involved in drug absorption, distribution, metabolism, and excretion (ADME) pathways. Out of 44 known ADME proteins in plasma EVs, previously annotated mouse cytochrome P450 3A11 (Cyp3a11), homolog to human CYP3A4, and uridine 5'-diphospho (UDP) glucuronosyltransferase 2A3 (Ugt2a3), increased upon daily rifampicin dosage. Dasatinib, a tyrosine kinase inhibitor to treat leukemia, also elevated Cyp3a11 levels in plasma EVs, but to a lesser extent. Altogether, this study demonstrates that measuring drug enzymes in circulating EVs as an effective surrogate is highly feasible and may transform today's drug discovery and development for personalized medicine.

Peripheral immune cell profiling of double-hit lymphoma by mass cytometry.

BACKGROUND: Double-hit or Triple-hit lymphoma (DHL/THL) is a subset of high-grade B cell lymphoma harboring rearrangements of MYC and BCL2 and/or BCL6, and usually associate with aggressive profile, while current therapies tend to provide poor clinical outcomes and eventually relapsed. Further explorations of DHL at cellular and molecular levels are in demand to offer guidance for clinical activity. METHODS: We collected the peripheral blood of DHL patients and diffused large B cell lymphoma (DLBCL) patients from single institute and converted them into PBMC samples. Mass cytometry was then performed to characterize these samples by 42 antibody markers with samples of healthy people as control. We divided the immune cell subtypes based on the expression profile of surface antigens, and the proportion of each cell subtype was also analyzed. By comparing the data of the DLBCL group and the healthy group, we figured out the distinguished immune cell subtypes of DHL patients according to their abundance and marker expression level. We further analyzed the heterogeneity of DHL samples by pairwise comparison based on clinical characteristics. RESULTS: We found double-positive T cells (DPT) cells were in a significantly high percentage in DHL patients, whereas the ratio of double-negative T cells (DNT) was largely reduced in patients. Besides, CD38 was uniquely expressed at a high level on some naïve B cells of DHL patients, which could be a marker for the diagnosis of DHL (distinguishing from DLBCL), or even be a drug target for the treatment of DHL. In addition, we illustrated the heterogeneity of DHL patients in terms of immune cell landscape, and highlighted TP53 as a major factor that contributes to the heterogeneity of the T cells profile. CONCLUSION: Our study demonstrated the distinct peripheral immune cell profile of DHL patients by contrast to DLBCL patients and healthy people, as well as the heterogeneity within the DHL group, which could provide valuable guidance for the diagnosis and treatment of DHL.

A comprehensive single cell data analysis of lymphoblastoid cells reveals the role of super-enhancers in maintaining EBV latency.

We probed the lifecycle of Epstein-Barr virus (EBV) on a cell-by-cell basis using single cell RNA sequencing (scRNA-seq) data from nine publicly available lymphoblastoid cell lines (LCLs). While the majority of LCLs comprised cells containing EBV in the latent phase, two other clusters of cells were clearly evident and were distinguished by distinct expression of host and viral genes. Notably, both were high expressors of EBV LMP1/BNLF2 and BZLF1 compared to another cluster that expressed neither gene. The two novel clusters differed from each other in their expression of EBV lytic genes, including glycoprotein gene GP350. The first cluster, comprising GP350- LMP1hi cells, expressed high levels of HIF1A and was transcriptionally regulated by HIF1-α. Treatment of LCLs with Pevonedistat, a drug that enhances HIF1-α signaling, markedly induced this cluster. The second cluster, containing GP350+ LMP1hi cells, expressed EBV lytic genes. Host genes that are controlled by super-enhancers (SEs), such as transcription factors MYC and IRF4, had the lowest expression in this cluster. Functionally, the expression of genes regulated by MYC and IRF4 in GP350+ LMP1hi cells were lower compared to other cells. Indeed, induction of EBV lytic reactivation in EBV+ AKATA reduced the expression of these SE-regulated genes. Furthermore, CRISPR-mediated perturbation of the MYC or IRF4 SEs in LCLs induced the lytic EBV gene expression, suggesting that host SEs and/or SE target genes are required for maintenance of EBV latency. Collectively, our study revealed EBV-associated heterogeneity among LCLs that may have functional consequence on host and viral biology.

IKKß mediates homeostatic function in inflammation via competitively phosphorylating AMPK and IκBα.

Inhibitor of nuclear factor kappa-B kinase subunit beta (IKKß) is one of important kinases in inflammation to phosphorylate inhibitor of nuclear factor kappa-B (IκBα) and then activate nuclear factor kappa-B (NF-κB). Inhibition of IKKß has been a therapeutic strategy for inflammatory and autoimmune diseases. Here we report that IKKß is constitutively activated in healthy donors and healthy Ikkß C46A (cysteine 46 mutated to alanine) knock-in mice although they possess intensive IKKß-IκBα-NF-κB signaling activation. These indicate that IKKß activation probably plays homeostatic role instead of causing inflammation. Compared to Ikkß WT littermates, lipopolysaccharides (LPS) could induce high mortality rate in Ikkß C46A mice which is correlated to breaking the homeostasis by intensively activating p-IκBα-NF-κB signaling and inhibiting phosphorylation of 5' adenosine monophosphate-activated protein kinase (p-AMPK) expression. We then demonstrated that IKKß kinase domain (KD) phosphorylates AMPKα1 via interacting with residues Thr183, Ser184, and Thr388, while IKKß helix-loop-helix motifs is essential to phosphorylate IκBα according to the previous reports. Kinase assay further demonstrated that IKKß simultaneously catalyzes phosphorylation of AMPK and IκBα to mediate homeostasis. Accordingly, activation of AMPK rather than inhibition of IKKß could substantially rescue LPS-induced mortality in Ikkß C46A mice by rebuilding the homeostasis. We conclude that IKKß activates AMPK to restrict inflammation and IKKß mediates homeostatic function in inflammation via competitively phosphorylating AMPK and IκBα.

Altered pathways and targeted therapy in double hit lymphoma.

High-grade B-cell lymphoma with translocations involving MYC and BCL2 or BCL6, usually referred to as double hit lymphoma (DHL), is an aggressive hematological malignance with distinct genetic features and poor clinical prognosis. Current standard chemoimmunotherapy fails to confer satisfying outcomes and few targeted therapeutics are available for the treatment against DHL. Recently, the delineating of the genetic landscape in tumors has provided insight into both biology and targeted therapies. Therefore, it is essential to understand the altered signaling pathways of DHL to develop treatment strategies with better clinical benefits. Herein, we summarized the genetic alterations in the two DHL subtypes (DHL-BCL2 and DHL-BCL6). We further elucidate their implications on cellular processes, including anti-apoptosis, epigenetic regulations, B-cell receptor signaling, and immune escape. Ongoing and potential therapeutic strategies and targeted drugs steered by these alterations were reviewed accordingly. Based on these findings, we also discuss the therapeutic vulnerabilities that coincide with these genetic changes. We believe that the understanding of the DHL studies will provide insight into this disease and capacitate the finding of more effective treatment strategies.

5-arylalkynyl-2-benzoyl thiophene: a novel microtubule inhibitor exhibits antitumor activity without neurological toxicity.

The composition of microtubules involving several steps, including the polymerization and depolymerization of α-tubulin and ß-tubulin heterodimers. Microtubule-targeting agents can increase or inhibit microtubule polymerization, thereby disrupting the dynamic process and stalling cells in G2/M phase. Microtubule-targeting agents are generally cytotoxic, which neurological toxicity being one of the significant adverse events associated. We recently reported a novel 5-arylalkynyl-2-benzoyl thiophene (PST-3) that exhibited broad-spectrum cellular cytotoxicity and in vivo potency with high safety. PST-3 was a substrate of p-gp, which could not cross the blood-brain barrier and lead to less neurotoxicity. The antitumor activities in vitro demonstrated that PST-3 combined with the colchicine-binding site on microtubule, induces morphological changes, disrupts microtubule networks, inhibits polymerization of tubulin, arrests breast cancer cells in the G2/M phase of the cell cycle and induces apoptosis. Evaluation of the antitumor effect in vivo demonstrated that PST-3 elicited MDA-MB-468 tumor %T/C of 11.75%, whereas elicited MCF7 tumor %T/C of 44.38% in breast cancer xenograft models. Besides, in vivo experiments of a higher dose (60 mg/kg) of PST-3 treatment for 21 days did not produce any significant neurotoxicity. These results provide evidence that PST-3 might possess the potential to be developed into a new microtubule inhibitor without neurological toxicity.

Synthesis and identification of lithocholic acid 3-sulfate as RORγt ligand to inhibit Th17 cell differentiation.

Primary bile acids (BAs), products of cholesterol metabolism and clearance, are synthesized in the liver and released into the intestine to facilitate the digestion and absorption of lipids. BAs are further converted by gut commensal bacteria into secondary colonic BAs and the metabolism disorder is closely linked to cholestatic liver diseases via regulating immune response. However, the effect and underlying mechanism of these host-microorganism biliary metabolites on T lymphocyte remain unclear. In the current study, we synthesized a sulfated product of lithocholic acid (LCA), lithocholic acid 3-sulfate (LCA-3-S), and investigated the binding affinity of the BAs metabolites on RORγt, the transcription factor of IL-17A. Our results demonstrated that the sulfate of LCA, LCA-3-S, exhibited better effect than its oxidated metabolite, 3-oxo-LCA, binding to RORγt. The results further demonstrated that LCA-3-S selectively suppressed Th17 cell differentiation without influence on Th1, Th2, and Treg cells. Collectively, we synthesized the sulfated biliary metabolite LCA-3-S and demonstrated that LCA-3-S selectively inhibited Th17 cell differentiation by targeting RORγt, indicating that metabolite disorder of BAs resulting in the decrease of LCA-3-S probably contributes to the pathogenesis of cholestatic liver diseases.

Development of CpG oligodeoxynucleotide TLR9 agonists in anti-cancer therapy.

INTRODUCTION: Toll-like receptor-9(TLR9) can recognize the foreign unmethylated CpG DNA, and thus intrigue a strong Th1 response which plays a crucial role in the innate and adaptive immune responses. To date, CpG oligodeoxynucleotide (ODN)-based TLR9 agonists have undergone four generations. Each generations' breakthroughs in immune activation, safety profiles and pharmacokinetic properties were confirmed by both preclinical and clinical studies. AREAS COVERED: We reviewed the development and major clinical trials of TLR9 agonists and summarized the optimization strategies of each generation. The applications, limitations and prospects of TLR9 agonists in cancer immunotherapy are also discussed. EXPERT OPINION: Clinical trials of CpG ODN TLR9 agonists as a single agent demonstrated insufficient efficacy to reverse the immunosuppressive status of majority of patients with high tumor burden. Therefore, more efforts are now been carried out in combination with chemotherapy, radiotherapy and immunotherapy maintenance therapy as well as vaccine adjuvant. Importantly, the synergistic and complementary effect of TLR9 agonists and tumor immune checkpoint inhibitor therapy is expected to exert greater potential. On the other hand, the double-edged sword effect of TLR9 activation in tumor and toxic effect reported in combination therapies should be noted and further studies required.

Inhibiting ferroptosis: A novel approach for stroke therapeutics.

Stroke ranks as the second leading cause of death across the globe. Despite advances in stroke therapeutics, no US Food and Drug Administration (FDA)-approved drugs that can minimize neuronal injury and restore neurological function are clinically available. Ferroptosis, a regulated iron-dependent form of nonapoptotic cell death, has been shown to contribute to stroke-mediated neuronal damage. Inhibitors of ferroptosis have also been validated in several stroke models of ischemia or intracerebral hemorrhage. Herein, we review the therapeutic activity of inhibitors of ferroptosis in stroke models. We further summarize previously reported neuroprotectants that show protective effects in stroke models that have been recently validated as ferroptosis inhibitors. These findings reveal new mechanisms for neuroprotection and highlight the importance of ferroptosis during stroke processes.

Bruton's tyrosine kinase inhibitors in primary central nervous system lymphoma-evaluation of anti-tumor efficacy and brain distribution.

BACKGROUND: Primary central nervous system lymphoma (PCNSL) is an aggressive lymphoma confined to central nervous system. Current treatments including surgery, chemotherapy and whole-brain radiotherapy often fail to achieve satisfactory effect, especially in elderly. As a regimen in targeted therapy, Bruton's tyrosine kinase (BTK) inhibitor ibrutinib has been tested in several clinical trials against PCNSL, offering hope for patients unfit for chemotherapy. We aim to evaluate and compare the anti-PCNSL ability of three different BTK inhibitors, ibrutinib, zanubrutinib and tirabrutinib, providing direct evidence for the targeted therapy of PCNSL. METHODS: Retrospective study was done on patients who received ibrutinib-based therapy in our hospital. Cerebrospinal fluid (CSF) from one patient was collected to measure the concentration of ibrutinib. Inhibition assay and apoptosis assay were done on lymphoma cells to determine the anti-tumoral effects of three inhibitors. Pharmacokinetic study was conducted to evaluate their ability in penetrating blood brain barrier and distributing in brain. RESULTS: In retrospective study, we found three patients with PCNSL who had good clinical response to ibrutinib-based therapy (2 complete remission, 1 partial remission), which further support the use of BTK inhibitors in PCNSL. In vitro studies show that ibrutinib has the best anti-tumoral ability among three inhibitors. In vivo study on pharmacokinetic profiles indicate that both ibrutinib and tirabrutinib are good in distributing in brain parenchyma. CONCLUSIONS: In conclusion, our study results suggest that BTK inhibitors can be promising candidates for PCNSL treatment, preferring the use of ibrutinib and tirabrutinib as anti-PCNSL agents among the three inhibitors.

Identification of an IKKß inhibitor for inhibition of inflammation in vivo and in vitro.

Targeting on the IKKß to discover anti-inflammatory drugs has been launched for ten years, due to its predominant role in canonical NF-κB signaling. In the current study, we identified a novel IKKß inhibitor, ellipticine (ELL), an alkaloid isolated from Ochrosia elliptica and Rauvolfia sandwicensis. We found that ELL reduced the secretion and mRNA expression of TNF-α and IL-6 and decreased the protein expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in bone marrow derived macrophages (BMDMs) stimulated with LPS. In coincided with the results, ELL suppressed PGE2 and NO production in BMDMs. Underlying mechanistic study showed that ELL inhibited IκBα phosphorylation and degradation as well as NF-κB nuclear translocation, which was attributed to suppression of IKKα/ß activation. Furthermore, kinase assay and binding assay results indicated that ELL inhibited IKKß activity via directly binding to IKKß and in turn resulted in suppression of NF-κB signaling. To identify the binding sites of ELL on IKKß, IKKßC46A plasmid was prepared and the kinase assay was performed. The results demonstrated that the inhibitory effect of ELL on IKKß activity was impaired in the mutation, implying that anti-inflammatory effect of ELL was partially attributed to binding on cysteine 46. Furthermore, ELL up-regulated LC3 II expression and reduced p62 expression, suggesting that autophagy induction contributed to the anti-inflammatory effect of ELL as well. In coincided with the in vitro results, ELL increased the survival and antagonized the hypothermia in the mice with LPS-induced septic shock. Consistently, ELL reduced TNF-α and IL-6 production in the serum of the mice treated with LPS. Collectively, our study provides evidence that ELL is an IKKß inhibitor and has potential to be developed as a lead compound for treatment inflammatory diseases in the future.

GSH Activated Biotin-tagged Near-Infrared Probe for Efficient Cancer Imaging.

Tumor imaging tools with high specificity and sensitivity are needed to aid the boundary recognition in solid tumor diagnosis and surgical resection. In this study, we developed a near infra-red (NIR) probe (P6) for in vitro/in vivo tumor imaging on the basis of the dual strategy of cancer cell targeting and stimulus-dependent activation. The selective imaging capacity towards cancer cells of P6 was thoroughly investigated, and the potential mechanisms of endocytosis were preliminary explored. Methods: GSH-activated biotin labelled NIR probe (P6) was designed, synthesized and characterized. The GSH responsive properties were systematically illustrated through UV-vis, fluorescent tests and LC-MS analysis. In vitro fluorescent imaging of probe P6 was collected in various living cancer cell lines (i.e. SW480, HGC-27, H460, BxPC-3, KHOS) and normal cell lines (i.e. BEAS-2B, HLF-1, THP1) under confocal laser scanning microscopy. Probe P6 was further applied to image primary human cancer cells which were freshly isolated from the peritoneal carcinoma and rectal cancer patients. Serial sections of human tumor tissues were collected and sent for H&E (hematoxylin-eosin) staining and P6 imaging. Live fluorescent and photoacoustic imaging were used to investigate the in vivo imaging of P6 in both tumor and normal tissues in HGC-27 and KHOS xenograft model. Results: Probe P6 could be recognized and transported into cancer cells by tumor specific biotin receptors and efficiently be triggered by GSH to release fluorophore 4. In fact, the cellular uptake of P6 could be partially blocked by the addition of free biotin. Furthermore, probe P6 could image various cancer cell lines, as well as primary cancer cells, exhibiting a ten-fold increase in fluorescence intensity over normal cells. In freshly dissected cancer tissues, P6 fluorescent imaging distinguished the cancerous area under confocal laser scanning microscopy, which was exact the same area as indicated by H&E staining. We also found that P6 exhibited superior selectivity against cancer tissues by local injection. Conclusion: In this study, we developed a dual-modal NIR probe P6 with enhanced cellular uptake into cancer cells and environmental stimulus triggered fluorescence. Our strategy provided a novel insight into the development of imaging tools that could be potentially used for fluorescent image-guided cancer boundary recognition and possibly cancer diagnosis.

Construction and analysis of a lncRNA­miRNA­mRNA network based on competitive endogenous RNA reveals functional lncRNAs in diabetic cardiomyopathy.

Diabetic cardiomyopathy (DCM) is a major cause of mortality in patients with diabetes, particularly those with type 2 diabetes. Long non­coding RNAs (lncRNAs), including terminal differentiation­induced lncRNA (TINCR), myocardial infarction­associated transcript (MIAT) and H19, serve a key role in the regulation of DCM. MicroRNAs (miRNAs/miRs) can inhibit the expression of mRNA at the post­transcriptional level, whereas lncRNAs can mask the inhibitory effects of miRNAs on mRNA. Together, miRNAs and lncRNAs form a competitive endogenous non­coding RNA (ceRNA) network that regulates the occurrence and development of various diseases. However, the regulatory role of lncRNAs in DCM is unclear. In this study, a background network containing mRNAs, miRNAs and lncRNAs was constructed using starBase and a regulatory network of DCM was screened using Cytoscape. A functional lncRNA, X­inactive specific transcript (XIST), was identified in the disease network and the main miRNAs (miR­424­5p and miR­497­5p) that are regulated by XIST were further screened to obtain the ceRNA regulatory network of DCM. In conclusion, the results of this study revealed that lncRNAs may serve an important role in DCM and provided novel insights into the pathogenesis of DCM.

Paeoniflorin improves pressure overload-induced cardiac remodeling by modulating the MAPK signaling pathway in spontaneously hypertensive rats.

Paeoniflorin (PF) is a main bioactive component of the root of Paeonia lactiflora Pal, and previous investigations suggest that it may impact cardiac remodeling in spontaneous hypertensive rats (SHR) via the MAPK signaling pathway. Thus, the purpose of this investigation was to examine the impacts of paeoniflorin cardiac function in SHR rats. Cardiac function and blood pressure were observed using echocardiography and non-invasive tail pressure gauge. Heart histopathology was assessed by histological staining and transmission electron microscopy. Genomic sequencing was performed and signaling pathway enrichment analyzed the function of differentially expressed genes(DEGs). Biochemical kits were used to analyze the serum level of proinflammatory cytokines including TNF-α, IL-6 and MCP-1. qRT-PCR proved the mRNA expression of Ngfr, Grin2b, and Ntf4. MAPK pathways were determined via western blot. Paeoniflorin decreased blood pressure and increased hemodynamic indexes. 131 DEGs were identified (SHR vs. PF), and mainly enriched on the MAPK signaling pathway. Paeoniflorin reduced IL-6, MCP-1, Ngfr, Grin2b, and Ntf4, and also decreased p-JNK, p-Erk1/2, and p-p38 proteins compared with the SHR group. Paeoniflorin attenuated cardiac hypertrophy, cardiac fibrosis, and inflammation, and subsequently improved LV function. In conclusion, the cardioprotective role of paeoniflorin was associated with the inhibition of MAPK signaling pathway.

Synthesis, biological evaluation, and molecular docking investigation of 3-amidoindoles as potent tubulin polymerization inhibitors.

A series of novel 3-amidoindole derivatives possessing 3,4,5-trimethoxylphenyl groups were synthesized and evaluated for their antiproliferative and tubulin polymerization inhibitory activities. Some of them demonstrated moderate to potent activities in vitro against six cancer cell lines including MCF-7, MDA-MB-231, BT549, T47D, MDA-MB-468, and HS578T. The most active compound 27 inhibited the growth of T47D, BT549, and MDA-MB-231 cell lines with IC50 values at 0.04, 3.17, and 6.43 µM, respectively. Moreover, the flow cytometric analysis clearly revealed that compound 27 significantly inhibited growth of breast cancer cells through arresting cell cycle in G2/M phase via a concentration-dependent manner. In addition, the compound also exhibited the most potent anti-tubulin activity with IC50 values of 9.5 µM, which was remarkable, compared to CA-4. Furthermore, molecular docking analysis demonstrated the interaction of the compound 27 at the colchicine-binding site of tubulin. These preliminary results suggest that compound 27 is a very promising tubulin-binding agent and is worthy of further investigation aiming to the development of new potential anticancer agents.

Potent Antagonists of RORγt, Cardenolides from Calotropis gigantea, Exhibit Discrepant Effects on the Differentiation of T Lymphocyte Subsets.

RORγt is the master transcription factor of IL-17 cytokine expression and Th17 lymphocyte differentiation, which are responsible for the induction of many autoimmune diseases. Recently, RORγt has become an attractive target for drug development to treat these types of diseases, and the field of RORγt antagonist research is now extremely competitive. In our current study, molecular docking was applied to demonstrate that cardenolides, including uscharin, calactin, and calotropin derived from Calotropis gigantea, probably directly bind to RORγt. Therefore, the inhibitory effect was further validated using a luciferase reporter assay. Because RORγt is the key transcriptional factor for Th17 differentiation, the effects of these compounds on Th17 differentiation were studied by flow cytometry. The results showed that uscharin, calactin, and calotropin inhibited Th17 differentiation from 100 to 500 nM. Furthermore, uscharin had a better effect than digoxin, a well-known inverse agonist of RORγt, in reducing Th17 polarization. Additionally, the effects of the cardenolides on the differentiation of other Th lineages, including Th1, Th2, and Treg, were investigated. Uscharin suppressed Th1, Th2, and Treg cell differentiation, while calactin suppressed the differentiation of Th1 cells, and calotropin did not influence the other T cell subsets, indicating that calactin suppressed Th1 and Th17 differentiation, and calotropin selectively quenched Th17 polarization. Structural analysis of the three compounds showed that the selectivity of uscharin, calactin, and calotropin on the suppression of the different subsets of T cells is correlated to the minor differences in their chemical structures. Collectively, calactin and calotropin have greater potential to be developed as lead compounds than uscharin to treat autoimmune diseases mediated by Th17 and/or Th1 cells.

Capsaicin-loaded folic acid-conjugated lipid nanoparticles for enhanced therapeutic efficacy in ovarian cancers.

In this study, folic acid-conjugated lipid nanoparticles were successfully prepared to enhance the active targeting of capsaicin (CAP) in ovarian cancers. The particles were nanosized and exhibited a controlled release of drug in the physiological conditions. The folic acid (FA)-conjugated system exhibited a remarkably higher uptake of nanoparticles in the cancer cells compared to that of non-targeted system. The folate-conjugated CAP-loaded lipid nanoparticles (CFLN) upon interacting with cancer cells were internalized via receptor-mediated endocytosis mechanism and resulted in higher concentration in the cancer cells. Consistently, CFLN showed a remarkably higher toxic effect compared to that of non-targeted nanoparticle system. CFLN showed significantly higher cancer cell apoptosis with nearly 39% of cells in apoptosis chamber (early and late) compared to only ∼21% and ∼11% for CAP-loaded lipid nanoparticles (CLN) and CAP. The loading of drug in the lipid nanoparticle system extended the drug retention in the blood circulation and allowed the active targeting to specific cancer cells. The prolonged circulation of drug attributed to the antifouling property of polyethylene glycol molecule in the structure. Overall, study highlights that using targeting moiety could enhance the therapeutic response of nanomedicines in the treatment of solid tumors.